Etheramine Compounds

ABSTRACT

Embodiments described herein provide a compound that may be used in a variety of applications such as corrosion inhibition, additives for metalworking, mining reagents, epoxy curatives, emulsifiers, fuel or lubricant additives, surfactant manufacture, acid scavengers and asphalt additives. The compound has the following structure: 
     
       
         
         
             
             
         
       
         
         
           
             where R 1  is a methoxy group, 
             R 2 , R 3 , R 4  and R 5  are independently a hydrogen atom or an alkyl group, and 
             R 6  is an aminomethyl group.

FIELD

Embodiments described herein are generally related to aliphaticetheramines, and more specifically, to a cycloaliphatic etheramine.

BACKGROUND

Etheramines prepared from acrylonitrile are known asalkyloxypropylamines, which are used in a variety of applications suchas corrosion inhibition, additives for metalworking, mining reagents,epoxy curatives, emulsifiers, fuel or lubricant additives, surfactantmanufacture, acid scavengers and asphalt additives.

SUMMARY

Embodiments described herein provide an etheramine compound that may beused in a variety of applications such as corrosion inhibition,additives for metalworking, mining reagents, epoxy curatives,emulsifiers, fuel or lubricant additives, surfactant manufacture, acidscavengers and asphalt additives. The compound has the followingstructure:

where R₁ is a hydrogen atom or a methoxy group,R₂, R₃, R₄ and R₅ are independently a hydrogen atom or an alkyl group,andR₆ is an aminomethyl group.

In another embodiment, an etheramine compound includes the followingstructure:

where R₆ has the structure

R₇ is a hydrogen atom or the same as R₆,R₁ is a hydrogen atom or a methoxy group, andR₂, R₃, R₄ and R₅ are independently a hydrogen atom or an alkyl group.

In another embodiment, a method for forming an etheramine compoundincludes reacting 4-methylcyclohexane methanol or4-methoxymethylcyclohexane methanol with an alkene having a nitrilegroup to form an intermediate compound having the structure:

where R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅ areindependently a hydrogen atom or an alkyl group, and hydrogenating theintermediate compound to form the etheramine compound having thestructure:

where R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅ areindependently a hydrogen atom or an alkyl group.

In another embodiment, an etheramine compound is formed by a methodincluding reacting 4-methylcyclohexane methanol or4-methoxymethylcyclohexane methanol with an alkene having a nitrilegroup to form an intermediate compound having the structure:

where R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅ areindependently a hydrogen atom or an alkyl group, and hydrogenating theintermediate compound.

DETAILED DESCRIPTION

Embodiments described herein provide an etheramine compound that may beused in a variety of applications such as corrosion inhibition,additives for metalworking, mining reagents, epoxy curatives,emulsifiers, fuel or lubricant additives, surfactant manufacture, acidscavengers and asphalt additives. The etheramine compound has thefollowing structure:

where R₁ is a hydrogen atom or a methoxy group,R₂, R₃, R₄ and R₅ are independently a hydrogen atom or an alkyl group,andR₆ is an aminomethyl group.

The etheramine compound may also have the structure:

where R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅ areindependently a hydrogen atom or an alkyl group.

An etheramine compound having the structure:

where R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅ areindependently a hydrogen atom or an alkyl group, may be used in avariety of applications such as corrosion inhibition, additives formetalworking, mining reagents, epoxy curatives, emulsifiers, fuel orlubricant additives, surfactant manufacture, acid scavengers and asphaltadditives.

The etheramine compound may be formed by reacting 4-methylcyclohexanemethanol or 4-methoxymethylcyclohexane methanol with an alkene having anitrile group to form an intermediate compound having the followingstructure:

where R₁ is a hydrogen atom or a methoxy group,R₂, R₃, R₄ and R₅ are independently a hydrogen atom or an alkyl group,andR₆ is a nitrile group.

The intermediate compound may also have the structure:

where R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅ areindependently a hydrogen atom or an alkyl group.

The alkene having a nitrile group may be acrylonitrile or any suitablestraight or branched alkene having a nitrile group. The reactiontemperature may range from about −20 degrees Celsius to about 60 degreesCelsius, such as from about 19 degrees Celsius to about 33 degreesCelsius.

The reaction between 4-methylcyclohexane methanol or4-methoxymethylcyclohexane methanol and the alkene having a nitrilegroup may be a cyanoethylation reaction. In one embodiment,acrylonitrile is reacted with 4-methylcyclohexane methanol or4-methoxymethylcyclohexane methanol in a cyanoethylation reaction. Thecyanoethylation reaction may be reversible and equilibrium limited.Using an excess of acrylonitrile can provide a higher alcoholconversion. A base catalyst may be used to facilitate the reaction ofthe alcohols. Suitable base catalysts include alkali hydroxides, andalkali alkoxides such as sodium methylate, amines, guanidines, or solidbases such as KF on alumina. At the end of the cyanoethylation reactionthe catalyst may be neutralized to limit byproduct formation. Anysolvent that does not interfere with the reaction may also be employed.

Hydrogenation of the intermediate compound may be performed by reactingthe intermediate compound with hydrogen gas to form the etheraminecompound. The etheramine compound having the structure (I) may be aprimary amine. Alternatively, the etheramine compound may be a secondaryamine or tertiary amine having the following structure:

where R₆ has the following structure:

R₇ is a hydrogen atom or the same as R₆,R₁ is a hydrogen atom or a methoxy group, andR₂, R₃, R₄ and R₅ are independently a hydrogen atom or an alkyl group.

Different catalyst used in the hydrogenation reaction between theintermediate compound and hydrogen gas may determine whether theetheramine compound is a primary amine, secondary amine or tertiaryamine. Primary means that the etheramine compound includes at least 40%by weight of the primary amine. For example, a cobalt catalyst may causethe etheramine compound to be a primary amine, such that the amount ofprimary amine in the etheramine compound may be over 80% by weight.Secondary means that the etheramine compound includes at least 40% byweight of the secondary amine. For example, a nickel catalyst may causethe etheramine compound to be a secondary amine, such that the amount ofsecondary amine in the etheramine compound is over 40% by weight.Tertiary means that the etheramine compound includes at least 40% byweight of the tertiary amine. For example, a platinum catalyst may causethe etheramine compound to be a tertiary amine, such that the amount oftertiary amine in the etheramine compound is over 40% by weight.Formation of a primary amine may be also increased by the presence ofammonia in the hydrogenation reaction mixture to limit coupling at thenitrogen of the amine and the nitrile carbon.

The hydrogenation reaction may be carried out catalytically in batch orcontinuous reactors. Reduction with a hydrogen donor can also be appliedstoichiometrically. The hydrogenation reaction may be performed at atemperature between about 20 degrees Celsius and about 140 degreesCelsius, such as between about 80 degrees Celsius and about 120 degreesCelsius. The hydrogenation reaction may be performed between about 14.3psig and about 2000 psig.

In one embodiment, the etheramine compound is3-[(4-methylcyclohexyl)methyloxy]-1-propanamine and has the followingstructure:

The 3-[(4-methylcyclohexyl)methyloxy]-1-propanamine may be formed byreacting 4-methylcyclohexane methanol with acrylonitrile to form3-[(4-methylcyclohexyl)methyloxy]-1-propanenitrile, which has thefollowing structure:

3-[(4-methylcyclohexyl)methyloxy]-1-propanenitrile is then hydrogenatedin the presence of a cobalt catalyst and ammonia to form3-[(4-methylcyclohexyl)methyloxy]-1-propanamine, although secondary andtertiary amines may be present. If the catalyst used in thehydrogenation reaction is a nickel catalyst and no ammonia is present inthe reaction mixture, the product of the hydrogenation reaction may beiminobis{3-[(4-methylcyclohexyl)methyloxy]propane, which is a secondaryamine having the following structure:

If the catalyst used in the hydrogenation reaction is a platinumcatalyst and no ammonia is present in the reaction mixture, the productof the hydrogenation reaction may be a tertiary amine having thefollowing structure:

In one embodiment, a reactant, which is a mixture of 4-methylcyclohexanemethanol and 4-methoxymethylcyclohexane methanol, is reacted withacrylonitrile to form an intermediate compound, which is a mixture of3-[(4-methylcyclohexyl)methyloxy]-1-propanenitrile and 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanenitrile, which has the followingstructure:

The intermediate compound is then hydrogenated with a cobalt catalystand ammonia to form an etheramine compound, which is a mixture of3-[4(4-methylcyclohexyl)methyloxy]-1 -propanamine and 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanamine, which has the followingstructure:

If the catalyst used in the hydrogenation reaction is a nickel catalystand ammonia is not added to the reaction mixture, the etheraminecompound formed by the hydrogenation reaction may be a mixture ofiminobis{3-[(4-methylcyclohexyl)methyloxy]}propane and N-3-[(4-methyloxymethylcyclohexyl)methyloxy]propyl-3-[4-methylcyclohexyl]methyloxy]-1-propanamine,which has the following structure:

The etheramine compound, such as3-[(4-methylcyclohexyl)methyloxy]-1-propanamine, 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanamine,iminobis{3-[(4-methylcyclohexyl)methyloxy]}propane or N-3-[(4-methyloxymethylcyclohexyl)methyloxy]propyl-3-[4-methylcyclohexyl]methyloxy]-1-propanamine,is a novel etheramine compound that may be used as corrosion inhibitors,additives for metal working, silica flotation aids for the beneficiationof iron or phosphate ores, epoxy curatives, emulsifiers, fuel orlubricant additives, acid scavengers and asphalt additives. Theetheramine compound may be also used as a starting material to formethoxylated amine, amine oxide, quaternary ammonium or amphotericsurfactants. The intermediate compounds, such as3-[(4-methylcyclohexyl)methyloxy]-1 -propanenitrile and 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanenitrile, are also novel compounds.

The following examples are provided as illustrative examples and shallnot be construed as delimitive of the scope of the disclosurewhatsoever.

In one example, crude 4-methylcyclohexane methanol is used as thestarting material. 4-methylcyclohexane methanol is a byproduct from themanufacture of cyclohexanedimethanol. The starting material, crude4-methylcyclohexane methanol, in the following experiments, contained4-5% water, 81% 4-methoxymethylcyclohexane methanol, 5%4-methoxymethylcyclohexane methanol, and other impurities. Crude4-methylcyclohexane methanol was reacted with excess acrylonitrile usingsodium methylate catalyst to give an intermediate compound, which is aliquid containing suspended and crystallized solids. The intermediatecompound was analyzed using gas chromatography-mass spectrometry, whichidentified peaks associated with3-[(4-methylcyclohexyl)methyloxy]-1-propanenitrile and 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanenitrile.

In another example, distillation of crude 4-methylcyclohexane methanolwas conducted to remove water. The resulting 4-methylcyclohexanemethanol has 0.7% water by weight and a hydroxyl number of 427 mg KOH/g.Cyanoethylation was carried out by addition of acrylonitrile by syringepump to catalyzed 4-methylcyclohexane methanol (sodium methylate wasused as the catalyst). 1997.98 g of 4-methylcyclohexane methanol (15.20equivalents) was reacted with 835.7 g (15.75 mol) of acrylonitrile inthe presence of 5.26 g sodium methylate at a temperature between about19 degrees Celsius and about 33 degrees Celsius. The acrylonitrile wasadded over a period of about two hours. Infrared spectrophotometryanalysis of the reaction mixture indicated about 69% conversion. Another5.26 g of sodium methylate was added and the mixture was stirred for twohours and found to contain significant unreacted alcohol. After stirringfor about six hours an additional 48.2 g of acrylonitrile was added. Themixture was allowed to further react at about 20 degrees Celsius for 24hours. Then 3.63 g of acetic acid was added along with 23.5 g magnesiumsilicate and the slurry was heated to about 80 degrees Celsius. Theslurry was vacuum stripped at about 80 degrees Celsius and then filteredto obtain 2748 g of a clear and nearly colorless liquid having ahydroxyl number of 8.87 mg KOH/g, 0.5 ppm K and 0.8 ppm Na. The clearand nearly colorless liquid was identified to be3-[(4-methylcyclohexyl)methyloxy]-1-propanenitrile.

The 3-[(4-methylcyclohexyl)methyloxy]-1-propanenitrile was hydrogenatedin a tubular reactor over a solid form cobalt catalyst in the presenceof ammonia at about 120 degrees Celsius and 2000 psig.3-[(4-methylcyclohexyl)methyloxy]-1-propanenitrile was fed into thereactor at a rate of 100 g/h, ammonia was fed into the reactor at a rateof 70 g/h, and hydrogen gas was fed into the reactor at a rate of 50l/h. The effluent was a dark amber-orange liquid. The dark amber-orangeliquid was vacuum stripped to remove lights and analyzed. Gaschromatography/mass spectrometry gave m/z 185 for the major peaks, alongwith m/z 215, 353 and 383 for minor peaks. These correspond to3-[(4-methylcyclohexyl)methyloxy]-1-propanamine, 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanamine,iminobis{3-[(4-methylcyclohexyl)methyloxy]}propane and N-3-[(4-methyloxymethylcyclohexyl)methyloxy]propyl-3-[4-methylcyclohexyl]methyloxy]-1-propanamine.Nuclear magnetic resonance confirmed the presence of3-[(4-methylcyclohexyl)methyloxy]-1-propanamine and 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanamine.

The etheramine compound, such as3-[(4-methylcyclohexyl)methyloxy]-1-propanamine, 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanamine,iminobis{3-[(4-methylcyclohexyl)methyloxy]}propane or N-3-[(4-methyloxymethylcyclohexyl)methyloxy]propyl-3-[4-methylcyclohexyl]methyloxy]-1-propanamine,may be used for silica flotation in iron beneficiation. As high ironores have been depleted, minerals with a lower iron concentration areprocessed to meet iron demand. Smelters require iron concentrationshigher than concentration found in presently mined ores, thus forcingthe use of separation processes to beneficiate the iron. Silica is foundalong with iron in the mined ores. A commonly used separation process isthe reverse flotation of silica. Silica gangue is removed by flotationin water, concentrating the iron by leaving the iron behind, hence theterm reverse flotation. Before performing the reverse flotation, theslime formed by small particles may be beneficially removed byhydromechanical means. The etheramine compound may act as a collector toenhance the floatability of different mineral materials. The compoundmay act both as a collector and a frother, which is used to promote thecreation of a semi-stable froth.

The etheramine compound, such as3-[(4-methylcyclohexyl)methyloxy]-1-propanamine, 3-[(4-methoxymethylcyclohexyl)methyloxy]-1-propanamine,iminobis{3[(4-methylcyclohexyl)methyloxy]}propane or N-3-[(4-methyloxymethylcyclohexyl)methyloxy]propyl-3-[4-methylcyclohexyl]methyloxy]-1-propanamine,may be used for curing of an epoxy resin. In one example, the etheraminecompound having hydrogen equivalent mass of 98.0 (4.90 g) was mixed withARALDITE® GY1610, which is a liquid epoxy resin with equivalent mass of183 (9.15 g), in an aluminum weighing pan. Upon standing overnight, themixture became a hard, brittle solid.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A compound having the structure:

wherein R₁ is a hydrogen atom or a methoxy group, R₂, R₃, R₄ and R₅ areindependently a hydrogen atom or an alkyl group, and R₆ is a nitrilegroup or an aminomethyl group.
 2. The compound of claim 1, wherein thecompound has the structure:


3. The compound of claim 1, wherein the compound has the structure:


4. The compound of claim 1, wherein the compound has the structure:


5. The compound of claim 1, wherein the compound has the structure:


6. An etheramine compound having the structure:

wherein R₆ has the structure

R₇ is a hydrogen atom or the same as R₆, R₁ is a hydrogen atom or amethoxy group, and R₂, R₃, R₄ and R₅ are independently a hydrogen atomor an alkyl group.
 7. The etheramine compound of claim 6, wherein theetheramine compound has the structure:


8. The etheramine compound of claim 6, wherein the etheramine compoundhas the structure:


9. The etheramine compound of claim 6, wherein the etheramine compoundhas the structure:


10. A method for forming an etheramine compound, comprising: reacting4-methylcyclohexane methanol or 4-methoxymethylcyclohexane methanol withan alkene having a nitrile group to form an intermediate compound havingthe structure:

wherein R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅are independently a hydrogen atom or an alkyl group; and hydrogenatingthe intermediate compound to form the etheramine compound having thestructure:

wherein R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅are independently a hydrogen atom or an alkyl group.
 11. The method ofclaim 10, wherein the alkene having the nitrile group is acrylonitrile.12. The method of claim 10, wherein a cobalt catalyst is used for thehydrogenating of the intermediate compound.
 13. The method of claim 12,wherein the etheramine compound has the structure:


14. The method of claim 10, wherein a nickel catalyst is used for thehydrogenating of the intermediate compound.
 15. The method of claim 14,wherein the etheramine compound has the structure:


16. The method of claim 10, wherein a platinum catalyst is used for thehydrogenating of the intermediate compound.
 17. The method of claim 16,wherein the etheramine compound has the structure:


18. An etheramine compound formed by a method comprising: reacting4-methylcyclohexane methanol or 4-methoxymethylcyclohexane methanol withan alkene having a nitrile group to form an intermediate compound havingthe structure:

wherein R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅are independently a hydrogen atom or an alkyl group; and hydrogenatingthe intermediate compound.
 19. The etheramine compound of claim 18,wherein the etheramine compound has the structure:

wherein R₁ is a hydrogen atom or a methoxy group and R₂, R₃, R₄ and R₅are independently a hydrogen atom or an alkyl group.
 20. The etheraminecompound of claim 19, wherein the etheramine compound has the structure: